The five biggest U.S. weapon makers have donated more than $107,000 to Brown, aiming to boost him in what was a nasty race. That amount places him second among the “Big Five’s” recipients, trailing only the staunchest industry ally, House Armed Services Committee Chairman Howard “Buck” McKeon, R-Calif.

Defense firms have no interest in a Massachusetts liberal replacing the moderate, hawkish Brown.

2. Rep. Allen West, R-Fla. vs. Democratic challenger Patrick Murphy: West came into office in 2010 as a darling of the tea party movement, which led to a Republican romp in the midterm elections.

An Iraq war veteran and retired Army officer, West called for major cuts in government spending, which had some in Washington talking of big things for the Floridian.

He quickly became one of Capitol Hill’s most vocal critics of President Barack Obama. But West’s outspoken conservative approach appears to be wearing thin on some voters. The latest Sunshine State News/VSS poll showed him with a 1 percentage point lead over Murphy.

Still, the GOP would lose an attack dog who hails from a key swing state. And in these partisan times, every party leader needs a few attack dogs.

3. Rep. Roscoe Bartlett, R-Md., vs. Democratic challenger John Delaney: After almost two decades in the House, Bartlett is in trouble. RealClearPolitics.com lists the race as leaning toward Delaney.

During his 19-year House career, Bartlett climbed rows of the HASC chamber, eventually heading the influential tactical air and land forces subcommittee.

Sources credit Bartlett with being one of the HASC’s most technically knowledgeable members. In recent years, Bartlett hammered the Obama administration hard, at times acting as something like the bad cop when the panel’s GOP leadership appeared to be playing the good cops.

4. Republican George Allen vs. Democrat Tim Kaine: The former senator and governor have for months battled for the Virginia Senate seat soon to be vacated by retiring Democratic Sen. James Webb.

An average of polls calculated by RealClearPolitics.com gives Kaine a 1.8 percentage point edge on election day, but lists the race as a toss-up.

With a massive military and defense sector presence in Tidewater and Northern Virginia, there is a strong chance the winner would be interested in joining either the Senate Armed Services Committee or the upper chamber’s Appropriations Defense subcommittee.

5. Missouri Democratic Sen. Claire McCaskill vs. Rep. Todd Akin: During the summer months, this race was bitterly contested. And then came Akin’s controversial comments about rape that made the Missouri battle a national one.

McCaskill has been an active and vocal member of the Senate Armed Services Committee. And Akin is the outgoing chairman of the House Armed Services seapower and projection forces subcommittee.

Missouri is a key defense-industrial base and military state, so no matter who wins this crucial race, the winner likely will seek membership on one of the Senate’s defense panels.